app/views/devise/sessions/new.html.erb
<section class="login">
<h2>Sign in</h2>
<%= semantic_form_for(resource, as: resource_name, url: session_path(resource_name)) do |f| %>
<%= f.inputs do %>
<%= f.input :email, input_html: { autofocus: true } %>
<%= f.input :password, input_html: { autocomplete: 'off' } %>
<%= f.input :remember_me, as: :boolean,
label: false # This prevents the label from appearing twice
%>
<% end %>
<%= f.actions do %>
<%= f.action :submit, label: 'Sign in' %>
<% end %>
<% end %>
</section>